An airplane stringer is an longitudinal member in the fuselage, or a spanwise member in the wing, which transmits skin loads into the body frames or wing ribs. That is, an airplane fuselage is formed by a number of crosswise frame members to which are attached a number of lengthwise extending stringers. In turn, the skin of the airplane is fastened to the stringers to form the fuselage.
In addition to supporting the aircraft skin, stringers are used to support various wire bundles, air conditioning conduits, hydraulic lines and the like which extend fore and aft inside the fuselage. Conventionally, the wire bundles, conduits and lines have been attached to the stringers by clips.
Many commercial airplanes have used fuselage stringers which were configured with hat-shaped cross-sections. Some newer model airplanes will be using fuselage stringers which have S-shape cross-sections and others which have Z-shape cross-sections. Because of the change in cross-sectional configuration, the conventional clips which were used to attach the wire bundles and hydraulic lines to the older hat-shaped stringers cannot be used to attach these elements to the S-shape and Z-shape stringers.
A number of conventional clips have been disclosed. For example, U.S. Pat. No. 2,346,200 by Tinnerman discloses a fastening device for a stringer wherein the fastener has two legs which engage opposite sides of the stringer near one of its ends. Furthermore, U.S. Pat. No. 2,329,894 by Hall discloses a wiring fastener which extends around one end of an airplane S-shaped member.
It should be appreciated that a modern jet airliner uses thousands of stringer clips. Therefore it is important that these clips be easy to install. It is also important that once the clips are installed, they remain in place even when subjected to various vibrational and other forces which an airplane typically experiences.
It is therefore an object of the present invention to provide a clip apparatus for attaching various airplane components to stringers.
It is another object to provide a clip apparatus which can be installed simply and quickly.
It is still another object to provide a clip apparatus which remains in place when installed.